1. Field of the Invention
The present invention relates to an electrical connection substrate and a droplet discharge head. More specifically, the invention relates to a droplet discharge head including a substrate main body having an electrical connection through hole formed therein and an electrical connection substrate that electrically connects connection target members arranged on both sides of the substrate main body to each other through the electrical connection through hole.
2. Description of the Related Art
As an inkjet recording head in which a diaphragm is vibrated by a piezoelectric element and ink in a pressure chamber is discharged as an ink droplet from a nozzle by this vibration, there is known an inkjet recording head structured in which a driving IC and a wiring for driving the piezoelectric element are arranged on a top plate member such as a printed wiring board so that the driving IC is connected to an electrode on the piezoelectric element through a through hole formed in the top plate member. For example, Japanese Patent Application Laid-Open (JP-A) No. 2000-135790 discloses an inkjet recording head configured so that a through groove is formed in a fixed member (top plate member) and so that an electrode film of a piezoelectric element is connected to a driving IC by a metal thin film through this through groove.
Such an electrical connection structure has, however, the following disadvantage. Since a connection wiring is directly connected to the electrode film of the piezoelectric element by the thin film, the wiring may possibly be peeled off or broken due to a heat stress, a mechanical stress or the like.
Such a disadvantage may possibly not only occur to the top plate member of the inkjet recording head but also widely occur when connection target members on both sides of the substrate main body are electrically connected to each other through the through hole of the substrate main body.